Better Remote Connections for Desktop

**What problem would this solve?**
* The remote backend feature of the desktop app has several issues
* It does not follow redirects
* It cannot supply a client cert for hosts that require mTLS
* It does not have a way for the user to test the connection before enabling it
* It requires a new window, but when the connection doesn't work for any reason the window just never opens, it times out and you get a system dialog saying to disable it and re-open. There is no way to figure out what the error with the connection is

**What would a good outcome look like?**
* A version that connects in the same window
* A "test connection" button that shows what's working and any errors encountered

**Possible approaches**
* Route the ACP connection through the `main.ts` node process side for more control over the connection (certs, redirect following, etc) and relay that info to the renderer side

**Additional context**
N/A

- [x] I have verified this does not duplicate an existing feature request

Do not begin implementation until the issue reaches **Ready** on the [Goose Issues board](https://github.com/orgs/aaif-goose/projects/1).

La issue menziona il routing della connessione ACP attraverso il processo node di main.ts. Inizia esaminando il codice del backend remoto dell'app desktop, probabilmente nel file main.ts e nei moduli IPC correlati (comunicazione tra processi). Cerca la gestione delle connessioni e la segnalazione degli errori già esistenti. Un pulsante «testa connessione» richiederebbe modifiche alla UI nel renderer e nuovi messaggi IPC al processo principale. «Fatto» significa che la connessione può seguire i redirect, supportare i certificati client mTLS e mostrare gli errori diagnostici nella stessa finestra.

Scritto dal modello di indicizzazione a partire dal testo della issue.